Switching mechanism



2 Sheets-Sheet l E. D. MEAD ET AL SWITCHING MECHANISM Filed May 9, 1941V D E n M |I|| l|| EL m L M 7 4 DM W m M v Q m I N L |l|| o o o W v Q Q0 0 0 no Ir 0 Hl b i||r|| o 2 W t 0 June 1, 19 43.

June 1, E MEAD ETAL SWITCHING MECHANISM Filed May 9, 1941 2 Sheets-Sheet2 E. D. MEAD INVENTORS F MILLER Patented June 1, 1943 swrronmo MECHANISMEdward D. Mead, Caldwell, N. J and Victor F. Miller, Queens Village, N.Y., assignors to Bell Telephone Laboratories,

Incorporated, New

York, N. Y., a corporation of New York Application May 9, 1941, SerialNo. 392,658

6 Claims.

This invention relates to improvements in switching mechanisms andparticularly to switches of the relay or crossbar type for use inestablishing electrical connections.

It is an object of the invention to improve switches of this type tocause them to perform their function with greater accuracy andreliability.

Crossbar switches to which the present invention may be applied are wellknown in the art and consist essentially of contact sets arranged inhorizontal and vertical rows and means including a group of horizontaloperating bars intersecting a group of vertical operating barscontrolled by magnets. In some types of switche the horizontal operatingmembers are rotated in two directions so that connections may beestablished at either of two sets of contacts at an intersecting pointby the rotation of a horizontal bar in one direction or the other andthe rotation of a vertical bar in one direc tion. A crossbar switch ofthis latter type is disclosed in the patent to J. N. Reynolds 2,021,329of November 19, 1935.

The present invention has been disclosed in connection with a crossbarswitch of this latter type. In such switches the contact sets areassembled on vertical frame units on which two vertical rows of contactsets are mounted with their corresponding sets of horizontal rows ofcontact sets. Each of these vertical frame units is provided with knifeedges, at the upper and lower ends thereof, on which the correspondingvertical bar is rotatably mounted. The lower end of the vertical bar isheld in place on its knife edge by a flexible spring engaging the barand the upper end of the vertical bar is held in place on its knifeedgeby means of an L-shaped member overlapping the bar on the outsidethereof. With this mounting arrangement of the vertical bars it mayhappen during the operation of these bars that they will be slightlyshifted out of their proper adjustment on the knife edges, particularlyin regard to the upper ends of the bars.

It is a feature of the present invention to provide a means forpreventing these bars from being displaced in this manner. This meansconsists of a clip having a body member which is shaped to slip over ahorizontal projection on the vertical frame member and a flexible springextending from this body member that engages the vertical bar on theoutside thereof in position to hold the bar against the correspondingknife edge but which permits the free rotation of the bar on the knifeedges and at the same time prevents it from being dislocated.

The invention has been illustrated in the accompanying drawings inwhich:

Fig. 1 shows a front view of a crossbar switch construction of the typedisclosed inthe abovementioned patent and to which applicants inventionhas been applied;

Fig. 2 is a fragmentary side view of a vertical frame unit;

Fig. 3 is a top view of a vertical frame unit;

Fig. 4 is a fragmentary perspective of the vertical frame unit with theapplicants invention applied thereto;

Fig. 5 is a perspective of the clip member of the applicants invention;and

Fig. 6 is a cross section taken approximately on the line 6-6 of Fig. 2.

Referring now to the drawings, and particularly to Figs. 1, 2 and 3, theswitch structure, to which the applicants invention has been applied,may consist of a frame comprising the members I, 2, 3 and 4. This frameis mounted in any suitable manner on vertical upright members 5 and 6.In this frame are mounted five horizontal bars I and a series of tenvertical bars. The first and the last only of the vertical bars havebeen shown mounted on their respective vertical frame units. Thesevertical bars have been indicated with numerals 9 and i0, respectively,and are mounted at the upper and lower ends on knife edges on theassociated frame members. The frame member for the bar 8 is marked ll.Referring to this member I|,-it--is shown that it is provided at the topwith an extension I2 bent at right angles to the vertical portion of themember, and is fastened to the horizontal member I by means of avertical lug l3 and a screw. A similar arrangement is provided at thebottom of the frame member II to secure it to the horizontal framemember 2. The vertical bar 9, for example, as shown in Figs. 3 and 6 inparticular, is L-shaped and at the inner edge of this L thebar ismounted on the knife edge l4 so that the bar may swing freely on thisknife edge at the upper end and on a similar knife edge at the lower endby the operation of a magnet l5 acting on an armature 16 which isintegral with the bar 9. The bar 9 is held in place at the lever end onthe corresponding knife edge by a spring member I! engaged in a slot I8in the bar, and is held at the upper end on its knife edge by anL-shaped member 20 which is Welded or otherwise secured to the framemember II at 22 and extends over the bar by an extension 23 as shown inFig. 3. This L-shaped member on the inside of the extension 23 isprovided with a projection 24 which normally engages the front side ofthe member 9 to hold it in place in its normal position. Horizontal andvertical rows of contact strips mounted on the vertical units have alsobeen shown in Figs. 1 to 3. The first set of movable contacts in thefirst horizontal row has been marked 26 and the first vertical row ofstationary contacts has been marked 21, while the first set of movablecontacts of the second horizontal row has been marked 28. The horizontalrows of contacts at each crosspoint are adjacent to flexible springfingers 30 that may be lifted or lowered by operations of the horizontalbars 1 by magnet 32 or 33 through the armature 34 or 35 attached to thebar I. The lifting of a finger 39, by the rotation of a horizontal barI, will place the fingers in the position in front of, for example, thecontacts 26 and 21 and through the medium of an operating card (notshown) and the rotation of the vertical bar 9 cause connections to beestablished between contacts 21 and 26. Similarly, the finger 30 may belowered by rotation of the bar 1 in the opposite direction to causeconnections to be established between the contacts 28 and 21. A morecomplete description of the operation of the switch in this manner toselect and operate contacts at crosspoints of the horizontal andvertical bars may be had by referring to the above-mentioned patent.

Normally the vertical bar 9 will rotate on its knife edges in the usualmanner, but occasionally due to vibration or for other reasons the upperend of the bar 9 may be slightly dislocated from the knife edge l4 andthereby cause inaccurate operation of the switch. To prevent this fromoccurring,.the applicants clip member shown'in perspective in Fig. 5 hasbeen provided. It consists of a flat body portion 40 provided with twohooked or U-shaped extensions 4| and 42. The body portion 40 is alsoprovided with a right angle extension 43 from which is out a springportion 44 having a hooked end 45. As shown in Fig. 4, this clip membermay be slipped over the extension l2 of the frame member ll so that theU-shaped portions 4! and 42 will engage the sides of this member l2 whenthe clip is in place.

It should be noted that the U-shaped member 42 is slightly enlarged at46 so that when the clip is slipped over the'member l2, this enlargedportion 46 will engage the inner side of the bent-up extension I3 on thehorizontal member l2 to securely lock the clipin place. To facilitatethis mounting of the clip, the body portion 49 is slotted as shown at 59to make it slightly flexible.

The body portion 40 is provided with a slot 5| that will fit on the edge52 of the member H to further steady the clip. When the clip is 'mountedin this manner as shown in Figs. 4 and 6, the hooked end "of the spring44 will engage the outside corner or rounded edge of the bar 9 as shownat 53. This point of contact at 53 is diagonally opposite the knife edgeM on the frame member H and will, therefore, hold the bar securelyagainst the knife edge with the minimum amount of friction during therotation of the bar 9 on the knife edge.

Although the invention is illustrated herein as applied to switches ofthe crossbar type, it is also applicable to other types of switches,such as relays. In particular it may be used in multicontact relayswhere the armature or operating bar is pivoted on knife edges and servesto actuate a multiplicity of contact springs.

What is claimed is:

1. In a crossbar switch, horizontal and vertical intersecting contactmaking strips, horizontal and vertical intersecting operating bars,means for rotating said bars, a frame'member for each vertical barhaving knife edges on which the associated vertical bar is mounted forrotation, means responsive to the rotation of a horizontal bar and avertical bar for actuating sets of contact strips at the intersectingpoint, an extension on each frame, a member for each vertical bar havinga fiat portion and two opposite clip members extending therefromarranged to slip over the extension of an associated frame and providedwith a flexible spring projection extending from said flat portion toengage the associated vertical bar and press it against the knife edgeson the frame.

2. In a crossbar switch, horizontal and vertical intersecting bars, anarmature on each bar, a magnet for each armature for operating saidarmature so as to rotate the associated bar, a frame member for eachVertical bar having knife edges on which the associated bar is mountedfor rotation, a set of contact making strips at each intersecting pointof said bars, means responsive to the rotation of a horizontal bar and avertical bar for actuating sets of contact making strips at theintersecting point, a right angle extension on each frame member, a clipmounted on each extension and having a flexible lock member for lockingthe clip on the associated extension, said clip also having a springmember extending therefrom for normally pressing the associated verticalbar against the knife edges on the associated frame member to hold thebar in place.

3. In a crossbar switch, horizontal and vertical intersecting contactmaking springs, horizontal and vertical intersecting operating bars,means for rotating said bars, and a frame memher for each vertical bar,each vertical bar having an L-shaped mounting portion and each framemember having a knife edge portion arranged so that each vertical barengages at the inner corner of its L-shaped portion the knife edgeportion of the associated frame for rotation of said bar on said knifeedge, means responsive to the rotation of a horizontal bar and avertical bar for actuating sets of contact springs at the intersectingpoint and a resilient clip member frictionally mounted on each frame andyieldingly engaging the associated bar at the outside corner of theL-shaped portion thereof to press it against the associated knife edgeon the frame to keep said bar in place to permit said bar to rotatefreely on said knife edge.

4. A switching device including a frame member having knife edges, anoperating bar mounted for rotation on said knife edges, contactoperating mechanisms controlled by said bar, an extension on said frame,a holding member for retaining said bar on the knife edges, said holdingmember having a flat portion and two opposite clip members extendingtherefrom arranged to slip over said extension and lock the holdingmember in place on said extension and having a flexible springprojection extending from the flat portion and engaging the bar to pressit against the knife edges.

5. A switching device including a frame having a knife edge, anoperating bar .mounted for rotation on said knife edge, contactoperating mechanisms controlled by said bar, a member attached to saidframe for retaining said bar on said knife edge when the bar is innormal position, a rectangular extension on said frame having an angularprojection and a clip member for mounting on said rectangular extensionhaving a flat portion and two opposite U-shaped members extendingtherefrom, arranged to fit over said rectangular extension and aprojection on one of said U-shaped members arranged to engage saidangular projection to lock the clip member on said rectangularextension, said clip member having a resilient spring projectionextending from the flat portion to engage said bar to press it againstthe knife edge on said frame when the bar is moved from its normalposition to its actuated position.

6. A switching device including a frame having a knife edge, anoperating bar mounted for rotation on said knife edge, contact-operatingmechanisms controlled by said bar when moved from the normal position toan operated position, a member secured to said frame for holding saidbar against said knife edge only when said bar is in normal position, anextension on said frame, a clip mounted on said extension and havinglocking projections engaging said extension so as to retain said clip ina fixed position on said extension and having a flexible projectionengaging said bar to hold it engaged with the knife edge when the bar ismoved from its normal position to its actuated position.

EDWARD D. MEAD. VICTOR. F. MILLER.

